your not alone… i think
i started having this problem 2-3 months ago. when i export using quicktime conversion, i get the studdering, but out of compressor it’s fine. the only thing is that compressor takes like three times longer to render for me (when going hdv to some type of quicktime file). no one gave me a solution, but i was just thinking about that today.
unfortunately ive got no solutions.
maybe it’s quicktime?